The IWU Fraunhofer Institute for machine tools and metalworking has good reason to celebrate: a new type of adaptronic honing tool for precision manufacture of petrol and diesel piston engines. The resulting fine tolerances reduce the consumption of fuel and oil, and unwanted environmental emissions.
The IWU says that manufacturers are already able to create an almost perfectly circular match between cylinder lining and piston, but that the cylinder becomes deformed during subsequent assembly and normal operation. This results in a reduction in engine power output and an increase in fuel consumption. Likewise, the engine then requires more oil to lubricate the interface between cylinder and piston, which accounts for almost half the total friction.
The new tool overcomes this problem. The IWU says that the adaptronic honing tool forms a controlled inverse non-circular profile on the cylinder bore. Once assembled and installed, under normal operating conditions this geometry is very close to the cylinder’s ideal geometric shape. The IWU hopes that this deviation from the theoretically perfect circular shape can reduce fuel consumption by about three percent.
Further information can be obtained from the Fraunhofer IWU.